| 摘要 |
1277161 Foamed olefin polymer product MITSUBISHI PETROCHEMICAL CO Ltd 17 Sept 1970 [18 Sept 1969] 44477/70 Heading B5A Foamed products are formed from small pieces of pre-foamed olefin homopolymers or copolymers containing a foaming agent and having a mean volume less than 0À2 c.c. and a cell size less than 0À5 mm. The pieces are placed in a mould to occupy 95-150% of the mould volume and heated to a temperature between the melting point of the polymer and 50‹ C. higher than the melting point of the polymer to melt and weld the outside surfaces of the pieces. The pieces may be formed by dividing an extruded foam rod. The polymer may be polyethylene, polypropylene, polybutene, an ethylene/vinyl acetate copolymer, an ethylene/ acrylic acid oopolymer or an ethylene/propylene copolymer, and may be mixed with natural rubber, butyl rubber, ethylene/propylene rubber, styrene/butadiene copolymer, polyisobutylene or polystyrene. The mould, which may be metal, may be heated by steam passed into the mould. |
